Steel flue boiler



A Oct. 13, 1959 G. E. oLsEN STEEL FLUE BOILER :s sheets-sheet 2' Filed April 19, 1957 INVENTOR @asv-Av E OLsE/v Gef. 13, 1959 G. E. oLsEN 2,908,256

STEEL FLUE BOILER l Filed April 19,1957 s sheets-sheet s lNvENToR Gz/sm v E. OL SEN ATTOR United States Patent ntice alemania Patented Oct. 13, 1959 STEEL FLUE BOILER Gustav E. Olsen, Arverne, N.Y.

Application April 19, 1957, Serial No. 653,776

5 Claims. (Cl. 122-73) This invention relates to boilers for use with steam and hot water heating systems and for heating hot water for domestic and process uses and more particularlyrconcerns an improved steel yboiler having provision for internal or external Vfiring -utilizing any suitable and convenient fuel such as oil, gas or coal. It comprises an improvement of my prior Patent No. 2,749,887 granted June 12, 1956. l v

With the rising cost of building construction it is essential to maintain the cost'of materials used therein at the lowest possible level without sacrificing quality. This is particularly important in the case of heating systems for residences inasmuch as the mechanical equipment, its installation and subsequent operation comprise a substantial part of the cost and maintenance of the home'. yAccordingly, one objectv of the invention is to provide a novel and improved steel ue boiler capable of high operating eicien'cy withV resultant `fuel 'economy to the user and characterized by its simplicity of design and fabrication, dependability and relatively low manufacturing cost.

Another object Aof the invention resides in the provision of a novel Vand improved boiler utilizing a simple and eiective' arrangement ofeleinents that may be fabricated of sheet metal with lthe minimum of fabricating machinery and labor and with resultant savings. The 'simplicity of design of the 'subje`ot boileris further characterized by the improved intercommunicationl of the waterways of the several water containing elements. 4

Still another object of this invention resides in the novel and improved combination and arrangement of boiler elements for steam boilers and hot Water boilers that may be quickly and easily assembled to form a relatively light, strong, dependable 'and durable' structure that will operate at high heat transfer ratesl and eli-leiencies with consequent fuel savings to the home owner or other user. By reason of the improved design of this boiler it may be'fabricated to include provision for suitable fuel burning apparatus within the boiler' itself or such fuel burning apparatus may -be contained within a separate refractory-lined enclosure which may provide the support for the boiler on the boiler room floor.

Another object ofthe invention resides in the provision of a novel and improved internally-med steel boiler of unusual compactness, occupying less than usual floor area for its installation and operation in the boiler room. By reason of an improved arrangement of the structural elements, the internal'water and lire side surfaces are all readily accessible for inspection and cleaning and contribute to high operating eiciency and to low cost of maintenance in that damagevwhich may result from clogged nre side and water side surfaces can be avoided.

A further. object of the invention is the provision of a novel andirnproved boiler.

The above and other objects and advantages of the invention will become Amore apparent from the followi'n'g' description and accompanying .drawings forming part of this application.

VIn the drawings:

Fig. 1 is a perspective View of one embodiment of a boiler" in accordance with the invention;

IFig. 2 is an exploded perspective view of the boiler shown in Fig. 1;

Fig. 3 is a front view in partial section of the boiler shown in Fig. 1; and

Eig. 4 is a longitudinal cross sectional view of the boiler of `Fig'. 3 taken along the line 4-4 thereof.

The boiler `in accordance with ythe invention comprises essentially several basic elements which may be assembled by conventional welding or other processes to form a completed unit. These elements include inner andouter shells which form the water spaces between the sides and the top chamber portions ofthe boiler, a ue barreldisposed within the confining iirebox walls of the inner shell and comprising in effect a tubular water tank through which a plurality of flues extend for increasing the heat transfer eiciency of the boiler, front and rear transverse water circulating means attached to the under part uof the flue barrel and circulating water thereto and to the water legs between the inner and outerl shells and ka front plate closing the front end of theboiler to cause combustion gases arising from the rebox' to flow outwardly through the ues of the flue barrel and thence to the chimney. The boiler in accordance with the invention may also include suitable baiiles 'to further deflect the gases upwardly and about the flue barrelandthe'nce through the barrel to the chimney or other= suitable external flue. v

AIt will be apparenttwith reference to the drawings that thisl invention provides a relatively inexpensive, highly practical and completely dependable boiler applicable for both steam and hot water heating systems as well as 'for heating hot water for domestic'and processuses and one that can be simply and easily fabricated of sheet steel `plates with-great economy of material, basic and Vsimpler'nachinery and without the need `for highly trained personnel. vThe compactness ot the subject boiler resulting in smaller dimensions and relatively light weight for Iits'capacity contributes to easier handling in transportation and lower freight charges.

More specifically and with reference to the drawings the' outer and inner shells of a boiler in accordance with the invention are denoted generally by the numerals 10 and 11, respectively. Both shells are of substantially similar configuration with the inner shell 1v1 being somewhat srnaller in 4bothvwidth and height than the' outer shell in order to provide side water Vlegs V12 and a relatively large upper water chamber 13. The outer shell loin' the illustrated embodiment of the invention includes a circular top' portion 14 terminating in straight sides 15 and 1-6. One or more outlets l17 are provided in the Ltop of shell 1t) for the outward ow of steam or Water as `the case may be and ,theV bottom edges of the walls y .and 16 are provided with openings 18 for the c'onnection of washout and return lines to the boiler.

The inner shell 11 as pointed out above is of a configuration somewhat similar to the outer shell 10' in that it is provided with a rounded top section l19 and substantially straight side walls 20 and 21. The radius of thetop section 19 is smaller than the top 14 otthe outer shell It) and the side legs 20 and 21 are shorter than the legs 15 and 16 of the outer shell. In addition the inner shell 1.1 is further provided with a pair of flanges 20 and 21 formed integrally with the side walls 20 and 214, respectively, and of a width determined by the Width of the outer shell so that they'will form a bottom closure between the two shells as willpbe observed in Fig. 3. In some instances the bottoml closure pieces may be narrow lstrips of steel at the bottom edges of the shells in place of the integral anges.

To assemble the outer and inner shells the back edges of the shells and y11 are placed in approximate alignment with the outer shell spanning the inner shell and the two shells welded together along the edges 22 and 23 to form a water tight seal. The frontend back edges of the shells are later yclosed and sealed by plates 24 and 25,respectively, welded to the outer and inner shells to fo-rm the water tight compartments therebetween.

It will be observed that the inner shell includes front and rear openings 26 and 27 at the lower front and rear edges of the walls 20 and 21 in order to providetfor the` circulation of water through the transverse front and rear headers to be described. In addition the inner shell is provided with a top circulation opening 28 for communication between the flue barrel water space and the upper water chamber 13.

The iiue barrel denoted by the numeral 29, comprises a tubular outer member 30 of a length approximately equal to butY preferably longer than that of the outer shell 1'0. Within the tubular member' 30lthere are a `plurality of flues or tubes 31 forming combustion gas passages. These flues may be of any desirable contour although flues of relatively narrow cross-section for increased heat transfer are p-referred. Each ilue 3t1 is preferably formed with pointed t-op and bottom for avoidance of sediment and air-bubble deposit and adherence and for improved Water circulation past the bottom of the ilue in an upward direction effecting Ia streamlining of an otherwise interfering surface at right angles to the flow of water. Each iiue comprises a pair ofV side walls 32 have top and bottom portions 33 bent inwardly to form a pair of identical channel like members which rwhen welded together along their top and bottom edges Y33' form the completed flue. The flues may also in some instances be formed of one piece of plate appropriately anged to the'inal shape thus giving ybut one joint to be welded or the component parts may consist of more than the two pieces first described depending upon fabricating equipment being used. The flues 3=1 are mounted Within the barrel 30 by insertion through similarly contoured lopenings inthe `end ue head plates 37 and 38 at the ends of the flue barrel after which the end of the flues may be welded to the respective lue heads and the edges of the flue heads can be welded to the flue barrel to form a Water tight chamber. The ue barrel is further provided with a top opening- 39 to which a conduit 40 is welded for steam and water flow to the uppertwater chamber 13. In addition the lluebarrel-29 is provided with one or more openings 41, 42 for water passage conmunication with the front and rear transverse water circulating headers.

The liue barrel is supported within and spaced from the inner shell 11 as shown in the figures 'and is attached to the transverse front and `rear water header members generally denoted by the numerals 43 and 44, respectively.

These transverse water headers are substantially identical and therefore only the front header 43 will be described in detail.

This Water header includes a pair of spaced parallel elements 45 and 46 with .a closure base plate 47 which preferably extends outwardly beyond the plate `45 to form the bottom closure of the front flue box of the boiler. In the illustrated embodiment of the invention, plates 45 and 46 are bridged by spaced enclosure members 48 vand 49 welded to the members 45 and 46 with the ceri-V trally located opening on top of the header-being mated wti-h a similarly sized opening 41 in -the bottom of the flue barrel 29. This arrangement provides water circulation meansso that the welding of all edges tothose of theabutting member gives a completely sealed and Water tight header joined for water circulation to the side water legs and to the ilue barrel at the front and at the Tear. t

'I'he front and rear headers -43 and 44 described above 'are attached to the lower part of the ue barrel 279 with YVbly of ilues, flue heads and attached transverse bottom .been described as being one-piece elements, it is apparof Vthe ,combustion chamber.

of the rear water header 44. The ue barrel is preferably welded to both the front and rear headers to form Water-tight compartments therebetween. A coupling 40 connects the opening 39 on the top side of the flue barrel 29 with the opening 28 of the inner shell 11 to provide means for the flow of water upwardly from the flue barrel into chamber 13 deiined by the outer and inner shells \10 and 11 respectively.

For convenience in descniption of this invention, the outer shell structure was first described and then the innerstructure including the front and rear water headers attached to the llue barrel were described. In actual practice however, the flue barrel 29 and the front and rear headers 43 and 44, would normally be assembled, then the outer and inner shells would be assembled and joined toy each other. The combined `shells Would then be positioned spanning the ilue barrel with its complete assemconnected headers.V The lshell assembly would be welded Vto the flue barrel assembly along the edges of the bottom water headers and along the common edges of circulation connection 40 joining openings 39 and 28. Upper Water chamber 13 is then closed at each end by the Yattachment of plates 24 and 25 previously mentioned.

Withthe boiler assembled asidescribed above, it will beobserved that the inner shell 11 extends beyond the .outer shell and the flue barrel and forms togetherl with lthe iiange 47 of the front water header, the sides` of the front opening or flue box of the boiler. The front Yflue box is preferably closed by a suitable plate coverA 50,

removably secured by bolts 51, or other suitable fastening 5means. The rear portion of the ue barrel 29 in the in- .stant embodiment of the invention extends beyond 4the lrearedge'of shell 11 and the gas passage space bet-Ween the flue barrel and the inner shell l11 is closed gas-tight by aplate 25. The smoke outlet for the boiler may be arranged inrany desired manner and may comprise an external housing or smokebox 50 secured to rear closure :plate 25.

Withthe boiler as described above, provision is made for a separate combustion chamber, denoted in the drawings by the numeral 53'. This chamber may be of any suitable construction, such as asteel shell lined with a suitable refractory material and the boiler in accordance with the invention is ixedly lsecured to the top surfaces If desiredhowever, the four Water legs of the boiler may be elongated to provide an integral water-Walled combustion chamber or the sides of the outer shell 10 may beV extended downwardly beyond ,the bottom of the water legY to the oor to form an integral dry supporting base. In addition, While the various elements such as the outer and inner shells 10 and 11 have las longitudinal halves of steel pipe and welded to at side plates and the front and rear closure Isections 24 and ,25 may be formed of three or more separate elements in order to rconserve material by eliminatingwastage due to Ycutting the single closure pieces to the proper shape.

`According to the invention, the flue barrel 29 is spaced -from the inner shell 11 to provide for the ow of combustion gases from the combustion chamber below to the.

space about the outside of the llue barrel, andthen to the front flue box where the gases are directed rearwardly through flues 31 inthe flue barrel. This arrangement provides an exceedingly long -travel for the gases of com- KVbustion and `increases the Atransfer' of heat to the water fwithin ythe flue barrel and the .sidetwater legs between the shells.` Moreover, the gases in theirgpassage directed f l 1 about the flue barrelgive up- 'eat"directlyt'tlie` water in the water chamber 13 by virtueof thefelfectiveness of' the upper surface of inner' shell 112 Another advantage of this boiler' construction is the provision for the free flow of water between the several elements. The heated" waterv in the'side waterlegsflows directly upward into chamber V13withreplacement water currents from chamber 13 own'g'downwardly along the unheated outer sides of' shell 10.1 Water in the front and rear transverse headers' 43V and 44`rises' into the flue barrel through openingsv 41 and 42'a'nd thence upwardly past the pointed bottom ends ofI` th'eflues, then betweenthe narrow Waterways `between the' fles" and along;V the inner contour ofthe ilue barrel and' converging at the top ofthe liuc barrel above the pointed tops'of the flues after having traversed the contained heatingsrfa'ces toV flow thence through'fthe circulationconnect-ion 40fin'to` the upper water chamber' 13. The front` and rear'ftransverseheaders re'- ceive their water circulation from?` the side water legs throughcommon openings 26 and 27; f

By reason of t'ne irnprovedstructureanddesign-of the boiler complete simplicity is attained together with improved operation andfuel economyand the elimination of complicated and extensive water circulationconduits and other piping either -within the boiler or external thereto.

When the boiler is used with 4notl water or steam heatin'g systems, the return lines of the system yWould be connected to one or more of the openings 18 of the boiler 'While the ow header would be connected to the appropriatefopening' 17. Other openings,V 17 are for safety rvalveand steam or water gauges'. In reverse flow hot Water heating systems using forced pump circulation of the hot water through the system, the return connection may be made equally well to a connection 17 at the top of the boiler and the outwardly flowing water can be fed lto the system piping through one of the lower connections at 18. In addition one or more drain cocks or 'valves may be connected to other openings 18 (Fig. l) for the removal of sludge settling in the water legs While the opening 18 in the rear plate 25 may be used as a clean out or for attachment of a low water control. It will be observed that in view of the substantially unimpeded water circulation between the several elements that sludge accumulation if any will be carried to the water legs of the boiler from whence it can be easily blown on through the openings provided.

To increase the heat transfer eiciency of the flue gases as they pass through the boiler, steel baffle plates 54 and 55 singly or in ycombination may be placed in the side gas passages to baifle and divert the combustion gases between the flue barrel and the inner shell for a longer period of time by narrowing the exit opening between the barrel and the shell. This increases the gas velocity and length of gas travel and the heat transfer is thereby increased by more intimate scrubbing contact with the traversed heating surfaces. For convenience the broken arrows in each ligure are denoted by the letter A indicate the now of combustion products while the solid arrows B indicate the flow of water.

Another advantage of the invention is the arrangement of the elements which greatly facilitates internal inspection, access and installation of water heating coils for so-called tankless heaters and other purposes. This end is attained in the illustrated embodiment through the provision of `a relatively large opening 60 in the front wall 24 which is closed by a plate 61 that may be secured in place by bolts 62 or other suitable fastening means. The holes 63 in the 'front and rear walls 24 and 25 are for the purpose of attaching lifting facilities in the manufacture and installation and the openings 64 in the wall 24 are for the attachment of a water level sight glass 65 when the boiler is used for the generation of steam.

Under certain conditions it may be desirable to provide an additional access or cleanout opening which in the illustrated embodiment of the invention is closed by a plug 67". Thisy opening may 13e-'used' asl an alternate water feeding 'and return connection in which case, the transverse headers 43" and' 44 may be omitted and the manufacturing cost o'f the boiler reduced;

While only' one embodiment ofthe invention has been illustrated and described, it is apparentthat other modiiications, alterations Iand arrangements may be' made withoutv departing from" the true scope and spirit thereof.

What is claimed is:-

1. A boiler comprising an inverted, substantially U- shaped elongated hollow outer member, a U`shaped' inV` ner member spaced fromV said outer member, the inner surfaces of `said inner member' forming a reside surface; a hollow elongated tubular member having gasconveying flues extending therethrough?,` the! last said member being disposed betweenitlie legs of said U-shaped' inner member and in spaced Relationshipto'. said 'fireside surfaces thereof, means c'losi'n'g the-opening between one end of said tubular member and the adjoining end of the U-sh'aped inner member, a flue box? closure onf the other end of said U-shap'ed inner memberl Venclosing the" adjoining end of said tubular' member?, water circulating means coupling the upper side-"f said tubular member with the adjoiningl part' oflsaid' U-'shaped inner member and transversely positioned water circulating means within the boiler and beneath thetubular member, the last said circulating means coupling the under side of said tubular member with the lower part of ,said U-shaped inner member and wherein the last" said means comprises atleast one hollow transverse member disposedv beneath one end of said tubular member and secured in sealed', water circulating relationship to said tubular member and to the lower portion of said llshaped inner member.

2. A boiler comprising an inverted, substantially U- shaped elongated hollow outer member, a Uashaped inner member spaced from said outer member, the inner surfaces of said inner member forming a fireside surface, a hollow elongated tubular member having gas conveying nues extending therethrough, the last said member being -disposed between the legs of said U-shaped inner member and in spaced relationship to said reside surfaces thereof, means closing the opening between one end of said tubular member and the adjoining end of the inner U-shaped member, la flue box closure on the other end of said U-shaped inner member enclosing the adjoining end of said tubular member, water circulating means coupling the upper side of said tubular member with the adjoining part of said U-shaped inner member and transversely positioned water circulating means within the boiler and beneath the tubular member, the last said circulating means coupling the under side of said tubular member with the lower part of said U-shaped member and wherein the last said means comprises at least two spaced hollow transverse attached circulation members disposed beneath said tubular member and secured in sealed, 'water circulating relationship to said tubular member and to the lower portions of said U-shaped inner member.

3. A boiler comprising an inverted U-shaped outer shell, a second inverted U-shaped inner shell spaced within the first shell to provide relatively narrow water compartments between the legs of said U-shaped shells: and a relatively large compartment between the upper surfaces of said shells, means sealing the front, bottom and rear open end areas between said shells, an elongated tubular member including at least one water jlacketed tire ue therein disposed within and spaced from said inner shell to provide a iirst gas passage, a front closure clos ing the area dened by the inner shell and spaced from said tubular member to provide a second gas passage therebetween communicating with the rst gas passage, rear closure means closing the area between the inner shell land said tubular member, a combustion chamber beneath said tubular member and communicating with said lirst gas passage, said tubular member spanning said combustion chamber, baie means closing the opening between the lower front portionv of said vtubular member, the inner surface of said inner. shell and said combustion -chamberto direct ,the products of combustion produced in said combustion chamber upwardly into the iirst' gas passage land, about said tubular member, said combustion products then movin'gforwardly into the second lgas passage then through said tubular member for discharge to a llue, andwater circulating means coupling the tubular member with said large. water compartment. 4; A boiler comprising an inverted U-shaped outer shell, a. second inverted U-shaped inner shell spaced within the first shell to provide relatively narrow water cornpartrnents between the legs of said U-shaped shells and a relatively large compartment betweenl the upper surfaces of said shells, `meanssealing, the front, bottom and rear open end areas between said shells, an elongated tubular member including atrleast one Water jacketed fire lue therein disposed within said inner shell and spaced therefrom to form a `|gas passage, atleastone hollow transverse member disposed-beneath one end portion of said tubular member and secured in sealed, water circulating relationship to said tubular member and to the lower portion of said U-shaped inner member, a combustion chamber beneath lthe tubular member with said tubular member spanning said chamber, said chamber being in communication with said gas passage, bale means closing the opening between the lower front portion of lche tubular member and said inner shell to direct the products of combustion produced in lsaid combustion chamber upwardly and about said tubular member, said combustion products then moving forwardly for discharge through said tubular member, and water circulating means coupling the tubular member with said large water compartment.

5. A steel plate flue boiler comprising an inverted, substantially U-shaped outer shell having coplanar. leg portionsV and aconnecting top portion, a second substantially -U -shaped shell generally symmetrical'but 'smaller than the rst saidkshell and fdisposed'wthinthe iirst shell and hav ing at least the front edge 'extending appreciably beyond the corresponding front edge of the first shell, means sealing the shells one `to, the other to form a watertight corripar-tment therebetween including a relatively largeupper water chamber and relatively narrow co-planar water leg chambers, an elongated ltubular water chamber spaced from the inner surfaceof said inner shell with the front edge in at least close proximity to the plane ofthe front edlge of said outer shell, said chamber including at least one fire flue extending vlongitudinally through the said cha-mbe,v means closing the front of the innerV shell,

baffles between the lower front portion of the tubular member and the inner shell, means on the other end of said inner shell closing the space between the inner shell and the tubular member and water circulation 'meanscoupling the tubular chamber and the dhamber defined by the irst and second U-shaped shells. Y l

Y References Cited the le of this patent UNITED STATES PATENTS n 475,409 McAleenan r May 24,- 1892 1,593,600- Ross July 17, 1926 2,095,527 Meuk oct. 12, 1937 2,142,626 Anderson et a1 Jan. s, 1939 2,546,082 Anderson Mar. 20, 1951 2,749,887

olsen vJune 12, 1956 

